Constructing Hypoxia-Tolerant and Host Tumor-Enriched Aggregation-Induced Emission Photosensitizer for Suppressing Malignant Tumors Relapse and Metastasis.

Photodynamic immunotherapy is a promising treatment strategy that destroys primary tumors and inhibits the metastasis and relapse of distant tumors. As reactive oxygen species are an intermediary for triggering immune responses, photosensitizers (PSs) that can actively target and efficiently trigger oxidative stress are urgently required. Herein, pyrrolo[3,2-b]pyrrole as an electronic donor is introduced in acceptor-donor-acceptor skeleton PSs (TP-IS1 and TP-IS2) with aggregation-induced emission properties and high absorptivity. Meanwhile, pyrrolo[3,2-b]pyrrole derivatives innovatively prove their ability of type I photoreaction, indicating their promising hypoxia-tolerant advantages. Moreover, M1 macrophages depicting an ultrafast delivery through the cell-to-cell tunneling nanotube pathway emerge to construct TP-IS1@M1 by coating the photosensitizer TP-IS1. Under low concentration of TP-IS1@M1, an effective immune response of TP-IS1@M1 is demonstrated by releasing damage-associated molecular patterns, maturating dendritic cells, and vanishing the distant tumor. These findings reveal insights into developing hypoxia-tolerant PSs and an efficient delivery method with unprecedented performance against tumor metastasis.

Design of Photosensitive Cobalt Complex Intermediates and Their Application in the Green Syntheses of Molecules Containing the Quinazolin-4(3H)-imine Scaffold.

Cobalt/photoredox cooperative catalysis is a well-explored technology for visible-light photoredox catalysis. Recently, the photosensitivity of Co(II) complexes in homogeneous catalysis has aroused the interest of scientists. In this study, photosensitive Co(II) complex intermediates were designed to develop new synthetic methods. These intermediates, consisting of Co(II) and two substrate molecules, bind to O2 and absorb visible light over a wide spectral range, triggering in situ oxidative decarboxylation to produce molecules containing the quinazolin-4(3H)-imine scaffold. These reactions employed glyoxylic acid and ketoacids as new building blocks, and good to excellent yields of the corresponding products were obtained under mild reaction conditions using green and inexpensive reagents and solvents. These results are of importance since the design of Co-based photosensitive intermediates will aid in establishing novel methods for harnessing visible light and hence lead to innovation in organic syntheses.